A serious earthquake can be a terrible experience, and it is easy to forget safety measures(措施) in disorder(混乱). Fortunately, most earthquake safety measures are common sense, but if you forget everything else, re­member the following instructions: drop, cover, and hold on. Also, most of earthquake deaths hap­pen after the earthquake, so remember that the danger does not end when the shaking does!

     If you stay indoors during an earthquake, move away from unsupported areas and windows. Try to get under a doorway or another area of the building which is held up by strong beams(梁).  Stay under a table or desk only if it is very strong. Do not rush to lifts, because it is far safer to stay where you are. Cover your head with your arms around it and curl (蜷缩) into a ball, and wait for the shaking to stop.

     If you stay outdoors during an earthquake, move to an area which is as open as possible. Don't move to build­ings, electric poles and other objects which may fall during an earthquake and injure you. Protect your head and stay low to the ground till the shaking ends and it is safe to move.

     After an earthquake, many buildings are less strong, although they appear safe. If you stay indoors, move people from the building quickly and help disabled or injured people. Once outdoors, move well away from the building so that if it falls down, you will not be injured. Wait till public safety officials an­nounce that it is safe to stay indoors.

     By planning ahead and keeping calm during an earthquake, you can greatly increase your chances of survival(生存) without injury.

    What would the world be like if cars could drive themselves? Imagine seeing an empty car passing by on its way to pick up its owner, or a car full of passengers who are reading, listening to music or even sleeping, but none of them are worried about the road ahead.

Well, all of this could be the future of driving. There are several companies, including Google, working on driverless (无人驾驶的) cars, which are currently in the testing stages. If the tests are successful, these electric, self-driven cars could be available very soon. But, how is it possible for a car to drive itself?

    Cars already have many features allowing them to take over for drivers in certain situations. Some features include cars being able to park themselves, or slow down when they detect objects (物体) close by. They can also control the speed if there are dangerous conditions, such as snow or slippery (滑的) roads.

    Other features have also changed the way drivers react to some situations. Scientists and engineers believe, with the help of wireless signals, cameras and GPS, we are now at a stage where creatinga safe self-driving car might be possible.

    The self-driven car may be the answer to lowering the number of deadly (致命的) accidents caused by careless drivers or dangerous conditions. However, there are still some people who do not like the idea. American lawyer Whit Drake, for example, doesn't believe these cars are safe. He thinks the possibility of the technology making a mistake will be too high.

Gardening is a popular activity all around the world. But what about people who do not have the space to garden? Not to worry! Today, we will give you information about growing beautiful window boxes. 

Location and safety

Window boxes are not just for the outside edge of the window, they can also sit on other places such as, walls, porches, or front steps. This window box can be on the front steps to a home and the owners can entered their window boxes. 

But safety first: People do get killed by falling window boxes. Make sure your window boxes are safe so they will not come down in a storm. If you feel your window box could be unsafe, you can have an indoor window box.

Light and water

Before you choose plants, check your window box location for light and rain. Window boxes dry out faster than in-ground plants, so they need more water. And if a window box is close to a wall or other structure, it may not get enough rainwater. 

Even if all your windows get little sun, do not give up. You can get a great look using plants that love the shade. Many shade-loving plants like spiderworts and verbenas，have leaves in beautiful colors and interesting shapes. 

The "wow" factor

What gives some window boxes their "wow" factor while others are just so-so? Create a theme! This is a central idea for the plants. For example, you may have a window box that is all cactuses or all edible plants. Or you could select only purple violets or green basil, then you'll have a color-themed window box. 

Besides having a theme, upkeep is also important. You should cut off anything dead, water your window boxes often and change things a lot. 

In the Beijing Winter Olympics, we were treated to incredible displays of athletic talents as competitors took to the snow and ice. As a popular sport at the Winter Olympics, ski jumping is one of the best examples to showcase the "superhuman" power of athletes.

Ski jumpers soar into the air and appear to be almost flying in the sky. How do they achieve this? Physics can offer us an explanation of how they make it. It involves the use of the laws of aerodynamics (空气动力学) to fight against gravity and increase lift while reducing drag.

To understand how ski jumping works, we need to consider three elements: gravity, lift and drag. Gravity is the force that pulls us towards an object. Lift occurs when an object is moving through the air—as its surface comes into contact with air particles (微粒), the particles are pushed down and away from the object, allowing it to move up. At the same time, this interaction creates drag, and slows down an object's movement.

While there is nothing that the skiers can do about gravity, they can twist their bodies into positions that allow them to achieve greater lift and avoid as much drag as possible. According to the Smithsonian Magazine, "To do this, athletes try their best to make their skis and body nearly parallel to the ground and place their skis in a V-shape just outside the form of the body. This position increases the surface area that produces lift and puts them in the ideal angle that will also maximize (最大化) lift."

Because of how the sport works, athletes' equipment is strictly controlled according to weight and height in order to avoid any unfair advantages. This means suits must be tight in order to ensure athletes cannot use them as a way to gain more lift. For athletes, minor day-to-day water weight changes as little as 300 grams. It can mean that suits will not be tight enough according to their body mass indexes (体重指数).

Welcome to our city—Nanning. It is a beautiful city with many trees and flowers. So it is called "Green City". There are many nice places to visit. Come and enjoy your trip to Nanning.